Cation exchange—a common mechanism in the storage and release of biogenic amines stored in granules (vesicles)?

Abstract

Superfusion of phenylethylamine-, noradrenaline- [norepinephrine] or histamine-charged weak (carboxyl) cation-exchangers (IRC-50 and Duolite CS-100) with isotonic NaCl caused a release of the amines. Similarly, bovine chromaffin granules and nerve granule preparations from bovine splenic nerve, rat vas deferens and rat corpus striatum released their amine upon superfusion with the same solution. The courses of release from the synthetic and biogenic materials showed very similar characteristics and fitted the same exchange equations. The observations support the view that the matrices of the biogenic amine-storing granules have the properties of weak cation-exchanger materials with carboxyls as the cation-binding groups, and that the NaCl-induced release of the biogenic amines is due to cation exchange (Na+ .dblarw. amine+). The possibility that amine release in vivo is based on cation exchange is discussed.